1. Technical Field
The present invention relates to a test substrate unit and a test system for testing a semiconductor chip. In particular, the present invention relates to a test substrate unit and a test system for testing a plurality of semiconductor chips formed on a semiconductor wafer.
2. Related Art
For testing semiconductor chips, an apparatus is known that judges pass/fail of each of a plurality of semiconductor chips formed on a semiconductor wafer, as shown in Japanese Patent Application Publication No. 2002-222839. This apparatus can be provided with a probe card that is electrically connectable to a plurality of semiconductor chips en bloc. Related art is also described in International Publication WO 2003/062837.
Generally, the probe card is formed using a print substrate, as shown in Patent Document 2. By forming a plurality of probe pins on this print substrate, the resulting probe card can be electrically connected to a plurality of semiconductor chips en bloc.
One method for testing semiconductor chips involves using BOST circuits. In this case, the BOST circuits can be loaded on the probe card, but when testing a plurality of semiconductor chips on a semiconductor wafer, the number of necessary BOST circuits is large and it becomes difficult to load the BOST circuits on the print substrate of the probe card.
Another method for testing semiconductor chips involves using BIST circuits provided in the semiconductor chips. With this method, however, circuits that are not used for actual operation are formed in the semiconductor chips, and therefore the space for circuits that are used for actual operation is decreased.
When testing semiconductor chips, a variety of tests can be performed including a DC test to judge whether the DC power consumed by a semiconductor chip fulfills certain specifications, a function test to judge whether a semiconductor chip outputs a prescribed output signal in response to an input signal, and an analog test to judge whether the characteristics of the signal output by a semiconductor chip fulfill certain specifications. However, it is difficult to perform such a wide variety of tests using BOST circuits on the print substrate or BIST circuits in the semiconductor chips.